1. Field
The present invention generally relates to wireless communication systems and, in particular, to multi-carrier communication systems providing asymmetric modes of operation.
2. Background
A communication system may provide communication between a number of base stations and access terminals. Forward link or downlink refers to transmission from a base station to an access terminal. Reverse link or uplink refers to transmission from an access terminal to a base station. Each access terminal may communicate with one or more base stations on the forward and reverse links at a given moment, depending on whether the access terminal is active and whether the access terminal is in soft handoff.
Wireless communication systems are widely deployed to provide various types of communication (e.g., voice, data, etc.) to multiple users. Such systems may be based on code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), or other multiple access techniques. CDMA systems offer some desirable features, including increased system capacity. A CDMA system may be designed to implement one or more standards, such as IS-95, cdma2000, IS-856, W-CDMA, TD-SCDMA, and other standards.
In response to the growing demand for multimedia services and high-rate data, multi-carrier modulation has been proposed in wireless communication systems. There remains, for example, a challenge to provide efficient and robust multi-carrier communication systems.